The present invention relates to a steering wheel locking device that is installed in a smart ignition system.
A typical mechanical ignition key installed in a vehicle includes a cylinder lock. The cylinder lock permits a key cylinder to be rotated from a LOCK position (locked position) to an ACC position (actuation position) when a proper key is inserted in the key cylinder. When a driver turns the key cylinder using the key from the LOCK position to a START position via the ACC position and an ON position, the engine is started.
A steering wheel locking device that has the above mentioned ignition key prohibits the rotation of a steering shaft when a proper key is not inserted in the key cylinder. On the other hand, the cylinder lock permits the steering shaft to be rotated when the proper key is inserted in the key cylinder.
Instead of such mechanical ignition key, smart ignition systems, which do not have the cylinder lock, have come into wide use. In a smart ignition system, an ECU located in a vehicle cross-checks an identification code of a key that a driver carries against the identification code of each vehicle. The manipulation of the ignition switch for starting the engine is permitted based on the result of the cross-check.
That is, the ECU reads the identification code from a transmitter that the driver carries or the key inserted in a key cylinder. When the ECU determines that the identification code is proper, the ECU controls an electromagnetic solenoid and releases a lock pin, which restricts the rotation of the key cylinder.
In a steering wheel locking device installed in the smart ignition system, the ECU controls an actuator and permits the key cylinder to be rotated when the identification code of the key is proper. By rotating the key cylinder in this state, a lock bar, which restricts the rotation of a steering shaft, is released. Alternatively, the ECU controls the actuator and directly releases the lock bar when the identification code of the key is proper.
In the above mentioned steering wheel locking device, the steering shaft is locked in a state where the key is inserted in the key cylinder at the LOCK position. When the key cylinder is at the LOCK position, the steering shaft is always locked regardless of whether the key is inserted in the key cylinder. For example, when the key cylinder is rotated from the ACC position to the LOCK position using the key, the steering shaft is immediately locked. However, the driver feels uncomfortable because the steering shaft is locked even though the key is still inserted in the key cylinder.
Accordingly, it is an objective of the present invention to provide a steering wheel locking device installed in a smart ignition system. The steering wheel locking device has a mechanism to lock a steering wheel when a key is pulled out of a key cylinder.
To achieve the above objective, the present invention provides a steering wheel locking device, which is attached to a smart ignition system to lock a steering shaft. The device includes a rotor, a switch knob, a locking mechanism, and an unlock maintaining mechanism. The rotor has a key insertion portion. The rotor is rotated between a locked position and an actuation position. The switch knob rotates the rotor. The locking mechanism locks the steering shaft. When the rotor is rotated from the locked position to the actuation position, the locking mechanism releases the lock of the steering shaft. When the rotor is rotated from the locked position to the actuation position, the unlock maintaining mechanism maintains the locking mechanism unlocked. The unlock maintaining mechanism further includes a movable body. The movable body is moved by a key inserted in the key insertion portion. When the rotor is rotated from the actuation position to the locked position, the unlock maintaining mechanism maintains the locking mechanism unlocked by the engagement of the key and the movable body.
Other aspects and advantages of the invention will become apparent from the following description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.